Bad thing. Do not expect to find in the book an answer to the question, stated at the very beginning. As well as where to find the businesses worth investing to. The authors do not know. Or they do not say - may be just to give to the reader an idea to invite McKinsey to think together about these issues in corporate HQs.
Having delivered this baleful message, the book distinguishes between typical management techniques - measurement, control, which leads to operational excellence [called convergent thinking], and the type of observation, reflection and debate [called divergent thinking] which may lead to innovation. The book outlines methodologies which can be used to attempt to combine both convergent and divergent approaches within a firm. The book therefore takes one step further than Clayton Christensen's suggestion of setting up a separate entity to pursue a specific `blue sky' set of ideas. However it in no way underplays the seriousness of the threat of new product or new product cycles to the incumbent, successful corporations - indeed some of the examples given in the book as successes (Cisco, Corning) have since gone through major traumas in subsequent product and economic cycles.
The book seems to take explicit aim at Collin's book `Built to Last', saying that companies which have been longest in the Fortune 500 have underperformed the market - and expands this theme that the market, by having no emotional link to firms, will pick winners and punish the slow remorselessly. From an investors point of view, my interpretation of Foster's guidance would be to periodically pick the top performers in an index and sell those which don't make it to the top, regardless of past position; my interpretation of Collins is that eventually the tried and trusted firms win out. I think my money would be on Foster.
However in terms of management thinking Foster is definitely in the Thomas Kuhn, Giovanni Dosi, Clayton Christensen, Geoffrey Moore tradition of the intense difficulty of managing to be customer focused, operationally excellent and innovative simultaneously.